Continuous flow centrifuge



July 3o, 1968 R. J. EBBERT 3,394,879

CONTINUOUS FLOW CENTRIFUGE INVENTOR,

July 30, 1968 R. J. EBBERT CONTINUOUS FLOW CENTRFUGE Filed sept. 1,

2 Sheets-Sheet 2 United States Patent O 3,394,879 CONTINUOUS FLOWCENTRIFUGE Robert J. Ebbert, 185 E. Avon Road, Rochester, Mich. 48063Filed Sept. 1, 1966, Ser. No. 576,734

' 5 Claims. (Cl. 233-21) ABSTRACT OF THE DISCLOSURE This inventionrelates to cent-rifuges for removal of foreign particles from fluids,and more particularly to continuousow centrifuges in which theaccumulated solids are periodically removed from the centrifuge.

It is an object of the invention to provide a novel and improvedcontinuous iiow centrifuge in which the accumulated solids may beperiodically removed without stopping rotation of the machine.

It is another object to provide an improved centrifuge of this typewhich will greatly reduce the possibility of damaging vibration due towave disturbances during operation, a problem which is commonly presentin conventional type centrifuges.

It is also an object to provide an improved continuous liow centrifugeof this type in which the iiow rate may be easily controlled so as to beuniform.

It is another object to provide an improved centrifuge having thesecharacteristics, which is of relatively compact construction and iseconomical to manufacture and maintain.

Other objects, features and advantages of the present invention willbecome apparent from the subsequent description and the appended claim,taken in conjunction with the accompanying drawings, in which:

FIGURE 1 is a side elevational View in cross section of the centrifugeof this invention;

FIGURE 2 is a top plan View of the centrifuge, parts being broken away;and

FIGURE 3 is a fragmentary cross-sectional View in elevation taken alongthe line 3-3 of FIGURE 2 and showing the spaces between the radial guidevanes.

Briefly, the illustrated embodiment of the invention comprises acylindrical stationary casing which encloses a cylindrical rotatinghousing, the housing being of generally flat shape. The rotating housinghas a cylindrical outer wall, an inwardly extending annular flat lowerwall, and a fiat upper wall which is secured to a hollow shaft rotatablymounted in the cover of the stationary casing. Means are provided forcontinuously rotating this hollow shaft, and its attached housing, andliuid to be cleaned is delivered down through the shaft. A circular flatplate is secured slightly below the upper wall of the rotatable housingso that the liuid delivered down through the shaft `will flow outwardlyin the space between this plate and wall. Radially extending guide vanesare provided in this space Ito prevent spinning of the fluid.

The fluid will collect in the space surrounded by the outer portion ofthe upper wall, the outer wall, and the inwardly extending lower wall ofthe rotating housing, the entrained foreign particles being forcedoutwardly by centrifugal force against the outer housing wall. Aplurality of downwardly extending radially disposed rectangular plates,referred to as paddles, are provided at the outer portion of the upperhousing wall, the height of these paddles being substantially less thanthe height of the housing between its upper and lower walls. Thesepaddles ICC will serve to carry along the newly entering fluid at thesame angular velocity as the housing and the fluid within it. Thepaddles will also have the function of preventing the buildup of wavedisturbances which could be created during operation of the centrifuge,and which might otherwise result in a magnified disturbance causingharmful Vibration or shaking of the machine. Furthermore, the paddleswill tend to prevent the formation of such waves in the rotating fluidwhen the machine is disturbed by an outside force.

The cleaned liuid will exit past the inner edge of the annular lowerwall of the housing and be thrown outwardly to the fixed casing fromwhere it can be drained.

A solids removal scoop is also provided within the rotatable housing,this scoop being rotatably mounted on a vertical axis by a tubeextending down through the fixed casing, and being movable between aretracted position spaced radially inwardly from the outer housing wall,and an operative position adjacent this wall. The rotatable mountingtube for the scoop will receive the solids caught by it, these solidsbeing forced down into the shaft by a helically shaped vane.

Referring more particularly to the drawings, the centrifuge is generallyindicated at 11 and comprises an outer casing generally indicated at 12which is supported by a frame or stand, partially indicated at 13.Casing 12 is of flat cylindrical shape, having a cover 14 securedthereto by means of a flange 15 on the casing and bolts 16 extendingtherethrough. The lower portion 17 of the casing is saucer-shaped, alarge central opening 1S being formed therein. A circular dam 19 issecured to the interior of bottom 17 of the casing some distanceoutwardly from opening 18, and a drain opening 21 is formed in bottom 17immediately outwardly of darn 19.

A hollow shaft 22 extends downwardly through the central portion ofcasing cover 14. An antifriction bearing 23 is secured to cover 14 andsupports the lower end of shaft 22. A superstructure 24 is carried bycover 14 surrounding bearing 23 and extending upwardly therefrom, abearing 25 being supported by the upper end of the superstructure androtatably supporting the upper portion of shaft 22. An electric motor 26is secured to one side of said superstructure 24, and is connected tothe upper end of shaft 22 by a belt 27 and pulleys 28 and 29. Motor 26is of a type capable of rotating shaft 22 at sufficient speed to createthe centrifugal action described below. The upper end of shaft 22 isconnected by means (not shown) to a source of fluid which is to becleansed. Such uid may be heat treat quench oil, oil for electricaldischarge machines or any fluid having foreign particles capable ofremoval by centrifugal action.

A flange 31 is secured to the lower end of shaft 22 below cover 14, thisiiange supporting a centrifuge housing generally indicated at 32. Thishousing is of fiat cylindrical sha-pe, having an outer wall 33, an upperwall 34 and a lower wall 35. The weight of housing 32 and shaft 22, aswell as their attached parts, is carried by a collar 36 secured to shaft22 above bearing 23 and resting on bearing housing 37.

The inner portion of upper wall 34 of housing 32 is secured to flange 31by bolts 38, these bolts also passing through a fiat circular plate 39spaced a short distance below and parallel to wall 34. The outerdiameter of plate 39 is somewhat less than the diameter of outer wall 33of the housing. Flange 31 is centrally recessed to provide a chamber 41between shaft 22 and plate 39, this chamber leading outwardly to thespace between plate 39 and upper wall 34 of housing 32.

A plurality of radially extending guide vanes 42 are disposed in thespace between plate 39 and upper wall 34 of the housing. The shape ofthese guide Vanes is best seen in FIGURES 2 and 3, the vanes havingtapered inner ends 43 adjacent space 41 and extending outwardly past theouter edge of plate 39 to the vicinity of side wall 33 of the housing.Six such vanes are shown in the illustrated embodiment, although thenumber and shape of the vanes could be varied to suit requirements. Theshape of vanes 42 is such, however, that there will be no restriction ofoutward flow of the fluid as it passes downwardly through shaft 22 andoutwardly from space 41 into the spaces between the varies. Bolts 44 areprovided for securing the mid portions of vanes 42 to plate 39 and wall34 of the housing.

A plurality of radially disposed paddles 45 are secured to the outerportions of vanes 42 beyond the edge of plate 39, these paddlesextending downwardly about one-third of the distance from the upper wall34 to the lower wall 35 of housing 32. Paddles 45 are in the form ofplates which may be secured to vanes 42 by welding or similar fasteningmeans, and they are of rectangular shape. Six such paddles are shown inthe illustrated embodiment of the invention.

Lower wall 35 of housing 32 is spaced slightly above darn 19 and extendsinwardly a slight distance past this darn, the wall having a ratherlarge central opening 46. A fixed tube 47 extends upwardly through theinner portion of bottom 17 of casing 12 and past dam 19, this tubepassing upwardly through opening 46. The tube rotatably supports asolids removal tube 48 which extends therethrough. A scoop 49 is securedto the upper end of tube 48. The configuration of scoop 49 is best seenin FIG- URE 2, the scoop having a curved shape with a mouth 51 opposingthe direction of rotation of housing 32, which is indicated by the arrow52 in FIGURE 2. Tube 48 is rotatable along with scoop 49 to move thescoop from its operative position shown in dotted lines in FIGURE 2 to aretracted position shown in dot-dash lines in this figure. In itsoperative position, mouth 51 is very closely adjacent outer wall 33 ofhousing 32 and slightly above lower wall 35. In its retracted position,the scoop will be clear of the space between upper wall 34 and lowerwall 35, which is the space occupied by the fluid being cleansed, asdescribed below.

Scoop 49 is connected with the upper end of tube 48, and a curved guidevane 53 is provided at the juncture of the scoop and tube so as to guidesolids downwardly as they are forced to the interior of the scoop.

In operation, with scoop 49 in its retracted position, motor 26 willrotate shaft 22, housing 32 and their attached parts at high speed.Fluid to be cleansed will flow downwardly through shaft 22 and outwardlythrough chamber 41 and the spaces between guide vanes 42. The fluidmight occupy a volume indicated at 54 in FIGURE 2 between each adjacentpair of guide vanes. As the uid reaches the outer edge of plate 39, itwill flow into the volume surrounded by the outer portion of upper wall34, outer wall 33 and lower wall 35 of housing 32. This volume isindicated in dot-dash lines at 55 in FIGURE l. The fluid will graduallylill this volume, being held in position by centrifugal force. The uidwill of course contain entrained particles of dirt or other foreignmatter, and these will be forced outwardly against wall 33, eventuallyoccupying the volume indicated approximately by double dot-dash lines at55 in FIGURE l.

After the fluid completely occupies space 55, additional quantities offluid added to this volume will cause the cleaned fluid to pass theinner rim of wall 35 surrounding space 46, and the fluid will owoutwardly along the underside of wall 35 into the space 57 above bottom17 of casing 12 and outside dam 19. The fluid will collect in this spaceand will exit via drain 21.

When it is desired to remove the accumulated solids in volume 56, scoop49 will be rotated to its operative position as shown in dotted lines inFIGURE 2. Shaft 22, housing 32 and the parts attached thereto maycontinue to rotate during this portion of the operation, although CalCil

the fluid delivery to the top of shaft 22 may be halted in order toavoid unnecessary loss of fluid. The scoop will remove the solidsaccumulated in volume 56 along with some entrained uid, and these solidswill pass toward the inner end of scoop 49 and, guided by vane 53 willpass downwardly through tube 48. The scoop may then be returned to itsretracted position and the fluid inflow resumed through shaft 22.

The presence of paddles 42 constitutes a major feature of the presentinvention. It has been found that these paddles prevent the creation ofa vibration effect which has been found to exist in conventionalcentrifuges of this type. This vibration effect is normally created inthese conventional machines by some disturbance which creates a wave inthe fluid being cleansed. The wave apparently reinforces itself to adegree which creates violent shaking of the centrifuge, creating thepossibility of damage and in any cease reducing the life of the machine.

The presence of paddles for some reason prevents thesedisturbance-caused waves from becoming self-perpetuating or increasingin size, and has been found to practically eliminate the possibility ofvibration or shaking due to their occurrence. While the exact reasonsfor this phenomenon are not entirely known, the paddles do carry alongthe Huid in volume at substantially the same angular velocity as housing32, and this seems to have a beneficial effect. Moreover, the paddlesapparently act as dampers or barriers to prevent waves created in thefluid from traveling around the periphery of the housing to asubstantial degree, and this damping effect prevents reinforcement ofthe original wave by such travel.

It should be observed that since paddles 45 are substantially less inheight than the total distance -between the top and bottom of housing32, they will not interfere with the accumulation of solids in volume56, which will normally occur to an increasing depth in a downwarddirection.

While it will be apparent that the preferred embodiment of the inventiondisclosed is well calculated to fulfill the objects above stated, itwill be appreciated that the invention is susceptible to modification,variation and change without departing from the proper scope or fairmeaning of the subjoined claims.

What is claimed is:

1. In a continuous flow centrifuge, an outer casing, a housing rotatablymounted within said casing, said housing having a circumferential outerwall, an upper wall and a lower wall, a hollow shaft at one end of saidhousing and extending axially therefrom, means for rotating saidhousing, a circular plate secured below the upper wall of said housing,a space being formed between said one end of said shaft and the centralportion of said plate to receive fluid delivered through said shaft, theouter diameter of said plate being less than the diameter of said outerhousing wall, a plurality of guide vanes extending outwardly betweensaid plate and the upper wall of said housing, and a plurality ofpaddles disposed below said upper housing wall between the outer edge ofsaid plate and the outer wall of said housing, said paddles being ofsubstantially less height than the distance `between the upper and lowerwalls of said housing.

2. The combination according to claim 1, the upper edges of said paddlesbeing secured to the outer ends of said guide vanes.

3. The combination according to claim 1, the lower wall of said housingbeing of annular shape and extending inwardly from said outer wall aboutthe same distance as said paddles, whereby fluid acumulated in the spacebetween said upper and lower housing walls will be carried along by saidpaddles and will also overflow past the inner edge of said lower housingwall, and means on said casing for draining overflow fluid therefrom.

4. In a continuous flow centrifuge, an outer casing, having a cover, ahousing rotatably mounted within said casing, said housing having acircumferential outer wall, an

5 upper wall and a lower wall, a hollow shaft secured at one end to saidhousing and extending axially therefrom, said shaft extending throughsaid cover, a bearing housing secured to said cover, a bearing held bysaid bearing housing and rotatably supporting said shaft, a collar onsaid shaft resting on said bearing housing -to support the weight of theshaft and the housing secured thereto, a superstructure mounted on saidcover, an upper bearing carried by said superstructure and rotatablysupporting the upper end of said shaft, an electric motor carried bysaid superstructure and connected to said shaft, a circular platesecured below the upper wall of said housing, a space being formedbetween said one end of said shaft and the central portion of said plateto receive iiuid delivered through said shaft, the outer diameter ofsaid plate being less than the diameter of said outer housing wall, anda plurality of guide References Cited UNITED STATES PATENTS 487,055 11/1892 Ohlsson. 528,681 1l/1894 Ohlss-on 233--22 XR 884,830 4/ 1908Lindahl. 2,431,142 11/ 1947 Schutte 233-22 XR 3,075,693 1/1963 Dega233--28 XR 3,104,225 9/1963 Di Benedetto 233-28 HENRY T. KLINKSIEK,Primary Examiner.

